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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Research » Publications at this Location » Publication #173177
Title: CRYOPROBE 3D NMR OF ACETYLATED BALL-MILLED PINE CELL WALLS

Author
item Ralph, John
item LU, FACHUANG - UW-MADISON

Submitted to: Organic and Biomolecular Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2004
Publication Date: 10/15/2004
Citation: Ralph, J., Lu, F. 2004. Cryoprobe 3D NMR of acetylated ball-milled pine cell walls. Organic and Biomolecular Chemistry. 2:2714-2715.

Interpretive Summary: Currently, detailed structural examination of plant cell walls takes many months. Our main interest has been in a component called lignin which acts as the glue holding fibers together in the plant. But as valuable as it is for the plant, it is the lignin that limits the utilization of the plant fiber in various natural and industrial processes (including digestion of forages by ruminants, and chemical pulping to make fine paper). Just isolating a fraction of the lignin component is an extremely tedious affair; when done, however, we have only analyzed a fraction as small as about 15% of the lignin. Recently we realized a breakthrough in complete dissolution of the whole cell wall. We demonstrate here that it is possible for the first time to acquire 3-dimensional NMR (Nuclear Magnetic Resonance) Spectra on the whole cell wall fraction. The degree of detail proves to be extremely revealing and allows us to get much of the information that has previously only been garnered from laboriously isolated fractions; 3D NMR allows the structures of interest to be "isolated" from the complexity of all the other components, producing detailed spectra that rival those from isolated components. The methods described here are more demanding on NMR instrumentation but provide enhanced capabilities for more rapidly analyzing plant cell walls without the need for extensive component isolation steps. The method will allow more facile "screening" of mutant and transgenic plants in studies aimed at understanding the limits to utilization of plant cell wall resources.

Technical Abstract: 3D NMR of solubilized ball-milled pine cell walls reveals striking details of lignin units, right down to differentiating stereoisomers in the polymer. Such 3D spectral editing therefore overcomes the need to isolate wall components to study their structures